Target 1 "HERO" monster you control; send it to the Graveyard, also, after that, if it left the field by this effect, Special Summon 1 "Masked HERO" monster from your Extra Deck with the same Attribute that the sent monster had when it was on the field (its original Attribute, if face-down).
Being a Quick-play spell gives you lots of timings to activate this card.
Requires a Hero monster on the field to activate, otherwise a dead card in your hand.
A Hero can only change into a Masked Hero of the same attribute.
(This OTK is only possible because of a bug that doesn't half Anki's attack when he attacks directly with his effect and Titan Showdown is active.) Use Cosmic Cyclone to banish a spell/trap card and reduce your LP to make Titan Showdown active, then used masked change to special summon Masked HERO - Anki. Anki is able to attack your opponent directly and because of Titan Showdown he will deal 5600 damage. If your opponent does not control any spell/trap card for you to use Cosmic Cyclone on, you can turn on self-chain. First activate Masked Change on your HERO and then use Cosmic Cyclone on Masked Change, you will still be able to summon Anki with your LP reduced for Titan Showdown.
You can use Masked Change on an Extra deck Masked Hero you control to special summon another copy of himself from the Extra deck. Use this during the battle phase to gain extra attacks. Masked Hero Anki can do this most efficiently. Attack with your DARK Hero monster, activate Masked Change to special summon Masked Hero Anki and then let Anki destroy a monster. Anki will let you search a Masked Change from your deck, which you can use on him to special summon another Anki ready to attack. Repeat till your opponent runs out of monster.
Here is a list of masked hero monsters that can be summoned with Masked Change.
Drilldark lets you special summon another monster when it's summoned, this can let you use Mask Change on one of them without leaving your vulnerable to cards like Enemy Controller. Use Drilldark's effect to special summon Destiny HERO - Celestial so you can use its effect when it's in the graveyard. Vyon can also be pretty good since you can use its effect to send Destiny HERO - Malicious from your deck to the grave, then activate it from the grave to special summon another Malicious from your deck, which thins your deck as well as letting you use Mask Change using your deck as a resource.
Decider's effect lets you return a Destiny HERO monster from your grave at the end of the turn. This can let you use Mask Change on him after he attacks to return Decider back to your hand at the end of your turn.